<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <script src="./jq-3.6.0.js"></script>
    <style>
        .header {
            height: 40px;
            line-height: 40px;
            width: 250px;
            display: flex;
            text-align: center;
            margin: 0px auto;
        }
        
        .item {
            flex: 1;
            position: relative;
        }
        
        .item:hover {
            background-color: rgb(153, 153, 153);
        }
        
        .title-item {
            width: 100%;
            display: none;
            position: absolute;
            top: 40px;
        }
        
        .title-item div:hover {
            background-color: rgb(253, 245, 221);
        }
        
        .toggle {
            display: block;
        }
    </style>
</head>

<body>
    <div class="header">
        <div class="item">
            <div class="title">新浪</div>
            <div class="title-item">
                <div>私信</div>
                <div>评论</div>
                <div>@我</div>
            </div>
        </div>
        <div class="item">
            <div class="title">微博</div>
            <div class="title-item">
                <div>微博未评论</div>
                <div>评论</div>
            </div>
        </div>
        <div class="item">
            <div class="title">邮箱</div>
            <div class="title-item">
                <div>免费邮箱</div>

            </div>
        </div>
    </div>

</body>
<script>
    $('.item').hover(function() {
        $(this).children('.title-item').stop().slideToggle();
    })
</script>

</html>